This invention relates to a magnetic recording method, and more particularly to a thermo-magnetic recording method in which a thermal pattern in the form of an image is input to form a magnetic latent image.
In magnetic recording methods, a magnetic latent image is formed in a magnetic material by magnetization and is then made visible by the use of magnetic toner particles, namely, magnetization detection type coloring particles which include magnetic particles in a macromolecular resin for instance which are affected by a magnetic field. The visible image thus obtained is transferred onto a sheet or the like by an electrostatic or magnetic method, and is then fixed by heat or pressure.
The same process is again carried out when a magnetic latent image carrier, namely, the magnetic recording medium, after being subjected to magnetic toner removal, is advanced to the next developing cycle as it is, or when, with the magnetic latent image erased, a new latent image is formed.
In the above-described magnetic recording method, the magnetic latent image is, in general, formed by magnetization with a recording current being allowed to flow in the magnetic head adjacent to the magnetic recording medium according to the image signals.
In the case where such a magnetic head is used to form a magnetic latent image over the entire width of the magnetic recording head, in general, single or plural printing sections for magnetization, i.e., magnetic recording tracks with recording gaps are provided, and a magnetic recording operation is carried out by the combination of a recording operation (main scanning) in the direction of movement of the magnetic recording medium and a transverse scanning operation (auxiliary scanning) performed perpendicularly to the aforementioned direction.
According to this method, an accurate drive and control method for maintaining the auxiliary scanning intervals constant is required, or it is necessary to move the magnetic recording medium at a high speed to reduce the scanning time, or to move the magnetic recording medium at low speed to form an image through development and transfer. That is, a precise and expensive drive and control method including various operational modes is required.
For such a scanning magnetic head recording operation, a method has been proposed in which a so-called multi-magnetic-head array, in which magnetic recording tracks are provided over the entire image width with high density so as to meet the necessary resolution of the reproduced image, is used to record the image one picture element line at a time as the magnetic recording medium is moved.
With this multi-magnetic-head array, in order to attain sufficient resolution of the reproduced image, it is necessary to provide thin tracks (less than about 100 .mu.m in width) at intervals of about 100 .mu.m.
Furthermore, in order to reduce the recording current, it is necessary to provide coils of plural turns for these tracks; that is, small and intricate parts are necessary. In addition, because of the electromagnetic interference between adjacent tracks, the realization of such a multi-magnetic-head array is considerably difficult.
The prior art utilizing magnetic heads is as described above. A so-called "thermo-magnetic" recording method utilizing heat applying means to form an image has also been proposed.
In the thermo-magnetic recording method, a so-called "thermo-magnetic recording medium" whose magnetic characteristics are modulated by temperature is used, and the thermo-magnetic recording medium, which has been magnetized, is particularly heated to a temperature higher than the Curie temperature by selectively applying heat, so that the latter is demagnetized. Alternatively, an external magnetic field is applied to a magnetization thermo-magnetic recording medium simultaneously as heat is applied to the latter, to thereby selectively magnetize the heated portion.
Examples of the heat applying means used in the thermo-magnetic recording method are laser beams, a flash beam, and a thermal head array in which finely separated heat generating resistance elements are arranged in one or plural lines.
The above-described methods are disadvantageous in that, as high thermal energy is partially applied to the thermo-magnetic recording medium, the latter may be deformed, and, when using the laser beam, considerably high power is required.